Flexo is the most dynamic printing process of them all, and to be fair, it is also the oldest printing process that has re-invented itself. From the original ‘hot metal type’ to ‘soft polymer plates’ flexo is capable of process printing that Guttenberg could never have dreamed or imagined about.
A typical flexo press configuration
To view an example of animation explaining this process, as used in the Basic Flexographic Course. Click Here
In today’s fast turnaround, just-in-time, working environment flexo stands proud as being the most versatile and adaptable printing process that not only meets, but far exceeds customer expectations in its delivery and repeatability.
Flexography uses a flexible photopolymer plate that is exposed using a negative or more commonly with a laser to image directly onto the plate, the plates are then processed with chemicals or water to remove the unhardened polymer leaving a raised hardened printing surface. Lasers are also used to directly ablate or burn off the non-printing areas of the plate allowing the plate to be printed immediately it has been made.
Although Flexo’s dominance as a printing process has impacted every area of printing it has three main market sectors, these are corrugated, labels and flexible packaging and each has its own distinct press configurations that is used to achieve the best results.
Flexible packaging sector
Flexible packaging as its name suggests is generally a filmic material, but can be paper or metallised foil. Plastic film tends to stretch and to stop this happening presses have been developed with a large single impression cylinder with all the colour units bolted around it.
Once the filmic material enters onto the cylinder it cannot effectively move, allowing many colours to be printed in register at the same time. Both water-based and solvent-based inks are used. These presses run at 600 meters a minute but newer models are rated for 1000 metres a minute, that’s a kilometre a minute!
Label sector
Labels are produced on an in-line press.
The colour units are modular allowing a four to twelve colour press to be manufactured, the advantage of this type of press is that while the printer is running other value added activities like printing on both sides, perforating, slitting, folding, adding variable data can all be done at the same time. These presses run at 200 metres a minute but the end result is a finished product giving it huge advantages over other printing processes that have to wait for the ink to dry before doing the other processing steps.
Corrugated sector
Boxes are produced in single sheets rather then a continuous roll of substrate.
The corrugated sheet cannot bend around a cylinder so it follows a straight path through the machine. Just like the label machines, printers can have die-cutting and folding lines attached producing a finished product for the customer.
As I mentioned at the start, Flexo is the most dynamic printing process, just walk through any supermarket and you will see some of the best flexo flexible packaging, label and corrugated printing at this time.
With these press types, three ink types and an incredible flexibility with any material flexo can give the customer what they want. Come into the course and learn more about this incredible process for yourself.
printable version